Self-tapping Screw 1. Standard: DIN, ANSI, GB 2. Size: ST2.9 to ST6.3 3. Material: carbon steel, stainless steel Self-tapping Screw1. Standard: DIN, ANSI, GB and non-standard;2. Head: Pan, CSK, Oval3. Groove: Phillips, Slotted or Pozi4. Surface: no burr and nice brightness;5. Raw Material: bought from Group Company, with stable quality and completive price;6. Processing: by cold-forging machines, ...